"Table 4. Composition of headspace gas in sediment from Holes 991A, 992A, and 993A."					

"Core, section"	Depth (mbsf)	 C1 (ppmv)	C2 (ppmv)	C1/C2	C1 (uL/kg wet sediment)

164-991A-					
1H-5	6	5		100000	13
2H-4	13.6	31	0.5	62	86
3H-4	23.1	59	2	30	169
4H-4	32.6	432	2.9	149	1170
5H-4	42.1	29000	34.8	834	71800
6H-4	51.6	12200	14.8	823	43200

164-992A-					
1H-2	1.5	2		100000	10
2H-4	7.3	3	0.1	24	7
3H-4	16.8	13	0.2	65	38
4H-4	26.3	11	0.2	55	32
5H-4	35.8	25	0.5	50	71
6H-4	45.3	81	2.5	33	218

164-993A-					
1H-1	0	6	0.2	30	14
2X-5	7.9	20	0.2	80	47
3X-4	18.3	174	3.6	98	720
4X-4	27.5	7330	21	349	27500
5X-4	37.1	18100	55	329	44000
6X-2	43.7	1680	0.3	5600	5620

Notes: C1 = methane and C2 = ethane. C1/C2 = the methane/ethane ratio.